If the parents are pushing him to be more yeshivish, sending him to EY might be a disaster, unless they have family there who will keep a close eye on him.
Every boy and girl has their own personality and values, and trying to push them to be something they’re not happy is going to set them up for a difficult time. From what I’ve heard there is a real lack of supervision in the yeshivas there compared to here, and the temptations are just as strong., especially if there is no family close by for support.
If the family is well-educated but not extremely yeshivish it is’t reasonable to expect the son they have raised to be different. If there are problems that are not being mentioned, and I sense there might be, it would be better to get counseling or personalized advice. It might also be wise to – strange as it may seem – talk to the bochur himself and find out what he feels he needs. Trying to jam a square peg into a round hole damages both the peg and the hole.